1. Field of the Invention:
This invention relates generally to metal refining apparatus and more particularly to a versatile portable thermal metal refining apparatus for selectively reclaiming metals from a combination or mixture of a plurality of materials having varied melting temperatures.
2. Description of the Prior Art:
Metal refining furnaces have long been known in the prior art. The prior art metal refining furnaces may generally be classified according to the use to which they are put. A first class of metal refining apparatus, suitable for continuous refining operation over extended periods of time at a single location, is generally characterized by a large non-portable refining chamber of varied configurations, but substantially closed to retain heat conducted into the reduction chamber for continuoulsy reducing a load introduced therein. The reducing heat is typically generated remote from the reduction chamber proper by means of a hearth or the like and is directed or forced into or around the reduction chamber. Such refining apparatus is generally suitable for use in foundries for the refining of ores into readily mouldable metals. Besides being non-portable, refining apparatus falling within this first classification is typically not suitable for reclaiming different metals in successive, closely spaced reducing cycles. This results from the construction of the reduction chamber, which generally has an inner surface that is highly susceptible to contamination by the last reduced metal, which would carry over undesired impurities into the reclamation cycle of a different metal on a successive reduction cycle.
The recent emphasis on resource conservation has led to increased demand for salvaging and reclaiming metals from combinations or mixtures of a plurality of scrap metals or the like for subsequent reprocessing. This has given rise to a second classification of refining apparatus, generally characterized by its ease of portability amoung a plurality of reclamation sites. Refining apparatus within this classification should ideally display the characteristics of: ease of portability, simplicity of use; reliable maintenance free operation; the capability of being completely operable from any one of a plurality of fuel sources available at the reduction site for producing the required reducing temperature; the capability of reclaiming different metals in successive reducing cycles without contamination from previous reduction cycles; ease of access to the reduction chamber proper for introducing loads of varied sizes and configurations; the flexibility of repetitively or continuously loading the reducing chamber without interruption to the reduction process; minimization of heat lose from the reduction chamber while permitting undesired impurities to be directly burned off by the reducing flame; ease of removal of molten metal and residue from the reduction chamber; and a plurality of reduction modes including rotating vs. nonrotating reduction chamber and retained puddling vs. continuous outflow reducing techniques for enabling the reclamation of a plurality of metals having a wide spectrum of melting temperatures and preferred reduction techniques.
Portable metal refining apparatus within this second classification has been designed which satisfy several of the above criteria; but none of such prior art portable refining apparatus simultaneously satisfies each of the desired operative characteristics for such apparatus. One such portable metal refining device of the prior art employs a pivotally mounted non-rotating refining crucible having an open end for loading access to-the reduction crucible and means for directing a reducing flame toward the closed end of the crucible. This apparatus while providing several of the desired characteristics, provides only one reduction mode (i.e. reduction in a puddling mode, with the crucible, having its open end tilted upwardly to retain its load and reduced molten metal toward the closed end) and requires a cumbersome block and tackle apparatus for lowering the open end of the crucible following a reduction cycle for pouring the reduced molten metal therefrom. Further, this apparatus does not provide for operative rotation of the reduction chamber or for continuous reducing operation in a non-puddling mode wherein the metal as reduced continuously flows out of the reduction chamber, permits significant heat lose from the reduction chamber during the reducing process and is not suitable for reclaiming different metals in successive reduction cycles without introducing impurities from earlier reduction cycles into the reclaimed metals of later reduction cycles.
The portable thermal metal refining apparatus of this invention overcomes these prior art disadvantages by providing a simple, efficient, rugged, flexible and relatively maintenance free apparatus which satisfies each of the above listed desired attributes for such a device. The portable refining apparatus of this invention is readily portable, is suitable for complete operative use with any one of a plurality of available fuel supplies and for selectively reclaiming a plurality of different metals having a broad spectrum of melting temperatures and offers the capability of reclaiming different metals in successive reducing cycles without carry-over of contaminants from a prior cycle into a successive reduction cycle.
While particular materials will be described in connection with the construction of a preferred embodiment of this invention, it will be understood that the invention is not limited to the use of these materials. Further, while particular support and motion imparting drive apparatus will be disclosed in connection with a preferred embodiment of this invention, it will be understood that other support and drive configurations could equally well be employed within the spirit and intent of this invention. Other variations will be pointed out within the following detailed description of a preferred embodiment of this invention following and will be understood to fall within the spirit and intent of this invention.